T4i and cold temperature
You need to put the camera in a Ziploc bag when going back into the warm air so condensation doesn't build up inside the camera. The condensation will build up on the inside of the bag instead. Putting some desiccant silica gel bags in there wouldn't be a bad idea either. Also be aware that this can also be an issue in the summer. If you are in your car with the AC going and you go outside into hot humid air the camera will fog up. You're better off keeping the camera in the trunk so that when you go out to use it there isn't that atmosphere shock.